On Saturday, Calgary, only dropped to 2.8°C, making it the second mildest low temp for November 23 on record. Not the most eye-popping stat, but digging deeper actually reveals the rarity of this warmth.
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Calgary’s average low is -11°C. So, not only is Saturday's low temperatures nearly 14°C above normal, it’s also 35°C warmer than the record low of -32.2° set in 1900.
This isn't however, a trend depicting an increase in warmth in recent years. Actually, three of the six years Calgary was below -30°C have been in the past 25 years.
Calgary’s continental climate makes the region very susceptible to extreme temperature variations during the transition months. November 23 has a 50°C difference between the record high and low. Comparing this to maritime climates such as Vancouver, or a meso-maritime climate like Toronto, where the temp differences are 27° and 29°C respectively.
ARCTIC CHILL SET-UP
This large temperature variation will be on display this week as arctic air returns to western Canada. A strong ridge is extending into Alaska while a deep trough is digging as far south as California. This set-up triggers a strong northeasterly flow across western Canada.
Upstream, a pool of frigid air is parked over Nunavut and will begin to flow into the western Prairies and filter through the mountains, eventually reaching the coast. This pattern can trigger arctic outflow conditions along the coast, but it also provides a dry, offshore flow, bringing lots of sunshine to southern BCitish .olumbia